honestly ryu...I think I gave you plenty of examples of differently shaded fires...? just pick one and dissect a still frame. you should be fine. for the size of fire you got, I would go to the metal slug level sheet I posted and use the small torch that is there as a model. that's probably pretty great.
USELESS ASIDE
That's just because I love trying to communicate the volume of fire, as futile as that is when we've got 3d fluid simulation...they pretty much do that "velvety" thing as the default effect for shitty commercial slides now =/.
/USELESS ASIDE
but the fullbright thing Kazuya suggested should work pretty well for your game. if you did that you could pretty much just keep the fire flat and ask your programmer to overlay an alpha enabled blur on it and call it a day. I always liked that look, it reminds me of 80's anime and american action movie sfx